UPDATE 2-Mexico heat wave triggers 'exceptional' power outages, president says

(New details throughout, adds power data in paragraph 4, quote in paragraph 6, water context in paragraph 11)

By David Alire Garcia and Adriana Barrera

MEXICO CITY, May 8 (Reuters) - Widespread recent power outages in Mexico were caused by unseasonably hot weather, the country's president said on Wednesday, assuring consumers that the national grid has sufficient generating capacity going forward.

President Andres Manuel Lopez Obrador told reporters at a regular government press conference that his government will also coordinate with private power producers, responsible for about half of Mexico's electricity generation.

Around 20 of Mexico's 32 states were affected by Tuesday's rolling power outages, according to data from grid operator CENACE analyzed by Reuters.

On Wednesday morning, net national power demand totaled around 44.9 gigawatts (GW), just under a net generation of 45.0 GW.

"This was something exceptional that was not expected," said Lopez Obrador, pointing in particular to a heat wave scorching parts of the country.

"But we're going to be very attentive to this special situation we're dealing with," he added.

COPARMEX, a major Mexican employers lobby, pitched more private investment especially for renewable energy as a way to improve the grid's reliability.

"The participation of private investment would provide stability in the face of the various contingencies and challenges of the national electricity system," it said. "The generation of clean energy and the creation of storage infrastructure could avoid future electricity emergencies."

Over the past six years, Lopez Obrador has sought to prioritize the dispatch of power from state-owned electricity company Comision Federal de Electricidad (CFE) while curtailing the growth of privately-owned generators, many of whom have seen their renewable energy plans stymied.

Tuesday's power outages struck as large parts of Mexico have also been grappling with severe water shortages, including upscale neighborhoods in Mexico City.

Water storage levels for the Cutzamala system, a major source of drinking water for much of the capital and the surrounding state of Mexico, has slid to less than 31% on Tuesday, according to data from national water authority CONAGUA. Experts have called that level critically low. (Reporting by David Alire Garcia and Adriana Barrera; Writing by Stefanie Eschenbacher;)